"Ted Wheeler is the right choice for job. He can bring together the community to take on the challenges we face and make progress on the issues that matter," Katz said in a prepared statement, released Wednesday by Wheeler's campaign. "Portland needs new leadership, Portland needs Ted Wheeler."

Katz served with Hales on the City Council from 1993 to 2002.

Wheeler, Oregon's state treasurer, also announced endorsement from former mayors Tom Potter and Sam Adams.

The endorsements represent a major political victory for Wheeler, who considers himself the underdog in the 2016 race. No Portland incumbent has lost a re-election bid since 1992.

Sarah Bott, a spokeswoman for Hales' re-election campaign, said she hadn't yet spoken to Hales (who is in a City Council meeting) and couldn't immediately comment.

UPDATE: Hales, in a statement, declined to address Katz's change but said he stands by his accomplishments.

"When you take office and have to make some big changes, it can certainly ruffle some feathers - especially with the people you have followed.""I appreciate that Mr. Wheeler has been hard at work on his campaign. I remain hard at work at City Hall and in the community tackling the very real issues facing Portlanders on a daily basis and making the kind of progressive change I was elected to do."

Other prepared quotes from Wheeler's announcement:

"Portland needs to reach its fuller potential to tackle issues like racial and economic inequality, public safety and climate change," said Adams, who won election in 2008 but did not seek re-election in 2012. "Ted Wheeler has the experience and progressive values to make this happen."

"Portland continues to grow into a diverse, vibrant community. It is critical that city government adapt to better include communities of color and other voices that have historically been pushed to the margins," said Potter, Portland's mayor from 2005 to 2008. "I am confident that Ted Wheeler has the commitment and passion to take on these important conversations and forge new relationships that ensure the will of the people is heard at City Hall."